For example, an example of known vibration isolation apparatuses is configured as follows: an inner hole is formed in a bracket member attached to a vehicle body; an internal cylinder member disposed in the inner hole of the bracket member is attached to a vibration source (such as an engine, a motor, and a transmission); and the inner surface of the inner hole and the outer surface of the internal cylinder member are connected through a vibration isolation leg formed of a rubber-like elastic material.
In recent years, it has been tried to form the bracket member using a resin for weight and cost reduction. For example, JP-A-Hei 8 (1996)-192442 (refer to FIG. 1, paragraphs [0013] and [0014]) discloses a resin bracket vibration isolation apparatus (vibration isolation apparatus) including: an elastic vibration isolation body 10 formed by sticking out an elastic column 16 (vibration isolation leg) from a rigid internal cylinder 14 (internal cylinder member) and bonding a rigid plate 18 (outer member) having an outer circumference greater than the elastic column 16 to an outer end of the elastic column 16; and a bracket 12 (bracket member) formed of a resin material and in which the elastic vibration isolation body 10 is inserted by insert molding.